62 



Subfamily V. My si nee. 



The essential characters are given in the synopsis on p. 1 1 — 12. The subfamily is extremely 

 rich, much richer than all the other five subfamilies together. On p. 12 — 13 I have divided it 

 into four tribes, all excepting the Heteromysini represented in the "Siboga" collection. 



Tribe i . Erythropini. 



To this tribe the following genera are referred: Erythrops G. O. S., Parerythrops G. O. S., 

 Metcrythrops Smith, Katerythrops Holt & Tatt., Dadylerythrops Holt & Tatt., Hypereryth-ops 

 Holt. & Tatt., Synei'ythrops n. gen., Pseudotnma G. O. S., Amblyops G. O. S., Parafublyops 

 Holt & Tatt., Dactylamblyops Holt & Tatt., lilctamblyops Tatt., Chalcophthalmus Illig, Holme- 

 siclla Ortm., Longithorax Illig, Gymnerythrops n. gen., Euchcetomera G. O. S. {Brtitomysis Chun), 

 Euchcstomeropsis Tatt., Mastigophthabmts Illig, Ccesaroviysis Ortmann, CImnoinysis Holt & Tatt. 

 and Arachno7nysis Chun. Seven of these genera are represented in the "Siboga" collection. 



Erythrops G. O. Sars. 



This genus has been very fully described by G. O. S.\RS in his fine monograph of the 

 Norwegian Mysidae. A single species has been secured by the "Siboga"; as a foot-note the 

 description of another species taken in the Gulf of Siam is added. 



34. Erythrops spinifcra n. sp. PL IX, figs. 3(7 — 3^:. 



Stat. 166. August 22. Lat. 2°28'.5S., long. i3i°3'.3E. 118 ni. Hard, coarse sand. Trawl. 

 2 specimens. 



Description. — This species, of which only an adult female and an immature specimen 

 are to hand, is allied to the Norwegian forms. The carapace has a small, triangular, acute 

 frontal plate or ro.stral process (fig. 3^:) which is broader than long; the front margin outside 

 this rostrum is concave but nearly straight towards the lateral margins. The eyes are extremely 

 large, depressed, dark reddish-brown. The antennal squama is five times as long as broad, its 

 outer margin straight, without serration, the marginal tooth proportionately long, the terminal 

 lobe as long as broad, reaching somewhat beyond the tooth. 



Uropods (fig. 3(^) with both rami slender, the exopod nine or ten times as long as broad. 

 The telson (fig. 3^) is very characteristic; it is half as long as the exopod of the uropods, one- 

 fourth again as long as broad, with the lateral margins somewhat concave and each furnished 

 with 10 — 13 spines, all moderately small excepting the terminal one which is much longer than 

 the others; the end is transverse, proportionately short, only between one-third and one-fourth of 

 the basal breadth, with two pairs of spines, both very long, but the inner pair somewhat longer 

 than the outer. In both specimens the two terminal spines of each half are inserted near each 

 other, while a good interval is found between the two spines of the inner pair; this interval 



